Apparatus for grinding gun barrels



Patented May 31, 1927.

v UNITED STATES JACOB LOWE YOUNG, OF NEW YORK, N. Y.

.AI'IPARATUS FOR GRINDING GUN BARBELS.

Application filed Ianuary 14, 1925. Serial No. 2,315.

This invention relates to the art of grinding the bores of gun barrelsand one of its objects is 'to provide an apparatus whereby the actualgrinding may be done by a suitable grinding paste such as carborundumpaste.

A further object of the invention is to provide means to readily feedthe grinding paste to the bore of thegun barrel during the grindingopeiation and to insure the uniform grinding of the bore.

. A still further object is to provide an apparatus, of the type abovementioned, of simple construction and designed to-facilitate themounting and adjustment of the gun barrels and tools for the grindingoperation.

In the drawings Fig. l is a top plan view of the grinding apparatus;

Fig. 2 a longitudinal section on the line 2-2 of Fig. 1; and

Fig. 3 a transverse section on the line 3 3 of Fig. 2. v

Referrin to the parts of the apparatus by numera s, 1 and 2 designate apair of spaced-parallel side rails rigidly supported by transversesupporting members 3 and 4.

Supported by the side rails 1 and 2 andadapted to slide longitudinallytherebetween is a carriagefor supporting the gun barrels to be ground.This carriage com rises a pair of transversely extending en members 5and (i'spaced apart almost the length of the gun barrels and rigidlyconnected together by rods 7 The opposed inner faces of the guide rails1 and 2 are formed with guide grooves 8 adapted to slidably receiveguide ribs 9 formed upon'the carriage end members 5 and 6. The carriageis thus supported for ion itudinal sliding movement between the si erails. Each of the carriage endmembers is formedat its upper edge with apair of notches 10 adapted to receive the barrels B of a double-barrelshot gun. The barrels are adapted to be removably secured to the members5 and 6 by means of clamping members 11 and 12- respectively. The saidclamping members are hinged to the carriage end members at one side ofthe gun barrels and are adapted to be extended across the barrels andpressed downwardl 'by means of thumb screws 13 adapted to e threadedinto the carriage end members.

The transverse rail-supporting member 4 has a pair of tool-drivingshafts 14 and 15 journaled in bearings therein and keyed to said shaftson the outer side of the member.

4 are meshing gears 16 and 17. The shaft- 14 1s power-driven by means,not shown, and through the gears 16and 17 rotates the shaft 15 in unisontherewith.

i A pair of tubular grinding tools 18 are lnserted through the breechends of the gun barrels prior to placing them upon the carriage. Thesetools are tapered to correspond to the taper of the choke bore 19.0f thebarrels and are of a length ,to extend entirely through the barrels andbeyond the muzzle. The breech end of each tool is closed and centrallyformed with a squared tapered extension 20. These ta ered extensions ofthe tools are adapte to be removably received in correspondingly shapedsockets 21 formed in the ends of the tooldriving shafts 14 and 15inwardly of the supporting member 4. This provides a centering anddriving connection for the tools. The muzzle ends of the tools are openand the tools are adapted to be rotatably supported within bearingscarried b the railsupporting member 3. The sai bearings are formed witha hinged upper half 22 adapted to extend across the tools and to besecured in place by a thumb screw 23. The space 24: within the tubulartools is adapted to be filled with a suitable grinding paste, such ascarborundum paste, prior to mountin the tools and the barrels forgrinding. i plunger 25 is inserted within the open end of each tool,said plungers being adapted to slidingl fit within the tools and havingoutward y extending operating stems 26 of material length. The space 18within the tool is in communication with the outer, or grinding face 27of the tool through perforations 28 spaced over the whole grinding face.

The outer ends of the plunger stems 26 are formed with spaced shoulders29 and between said shoulders the stems are adapted to be removablyreceived in upwardly opening notches 30 formed at the upper side of aplunger-operating crosshead 31. The crosshead 31 is slidably mountedbetween the side rails land 2, in a manner similar to the mounting ofthe gun barrel carriage, and is adapted to be moved longitudinally backand forth by means of a screw 32. The screw 32 is swiveled at one endupon across bar 33 fixed to the side rails, is. adapted, to

be turned by means of a knurled head 34, I

and is threaded through the cross head 31.

The gun barrels are adapted to be accurately adjusted with relation tothe grinding faces of the tools by means of an adjusting screw 35. Thisscrew is swiveled to the fixed cross bar 33 below the screw 32, extendsinwardly through the crosshead 31 and the rail-supporting member 3 andis threaded through the end member 5 of the gun barrel carria e. Thescrew 35 is adapted to be by a knob 36 having graduations around itsedge which cooperate with an index member 37 upon the bar 33 toaccurately indicate the carriage adjustment. When the carriage is movedto the right with reference to Figs. 1 and 2, by the screw, the internalsurfaces of the barrels are moved into closer contact with the taperedtools. Any thrust upon the tools resulting from said adjustment will bereceived b ball bearings 38 interposed between shou ders upon the driveshafts 14 and 15 and the inner face of rail-supporting member 4. Endwisemovement ofthe tools to the left is prevented by stop ribs 39 upon thetools which abut the tool hearings in the sup porting member 4.

When the gun barrels, the tools and the plungers have been properlyassembled and mounted in the apparatus for grinding the power is turnedon the shaft,l4 and both tools will be rotated. B turning theplunger-operating screw 32 tie plungers may be moved inwardly to forcethe grmding paste 'within the tools out through the perforations in thegrinding faces. This may be done whenever it is considered necessary inthe course of the rinding operation to supply more paste. he erforationsare closely spaced over the grin ing faces of the tools and thehydrostatic ressure caused by the movement of. the p on ers will forcethe paste out equally throng all of the perforations. The barrels willtherefore be ground uniformly. As the grinding progresses the barrelsmay be moved into closer contact with the tools to the required degreeby merely turning the screw knob 36. Q To remove the barrels afterthe'grindin is completed, the screw head 36 is turned back to retractthe barrel carriage and permit the tool-driving connections 20 and 21 tobe separated. The clamps 11 and 12 and the upper bearing member 22 arenext released and swung back. The barrels, the tools and the plungersare then free to be lifted from their supports as a unit. In order tofacilitate and speed up the grinding of a large number of barrels,several airs of tools and plungers may be provide for each apparatus inorder that one assembled unit of barrels, tools and plungers maybeinserted as soon as the first unit is removed. The removed tools arethen withdrawn from the ground barrels, inserted in a pair of ungroundbarrels and re-charged with paste,

if necessary, while the barrels mount-ed upon the apparatus are beingground.

What I claim is:

An apparatus for grinding the bore of a gun barrel comprising asupporting frame including track means; a carriage mounted to travelupon said track means and adapted to support a gun barrel; an elongated,hollow, tapered grinding tool formed with a perforated grinding face,said tool being open at'one end and closed at the other end and adaptedto be filled with inding paste; a plunger adapted to be shifted withinthe open end of the tool to force the paste out through the perforationsand provided with an outwardly projecting stem; a tool-rotating shaftmounted upon the supporting frame at one end of the track; a loosedrivshaft and the tool; bearing means designed to rotatably andreleasabl support the open ing connection between the closed end of saidend of the tool; releasab e clamping means to hold the barrel upon thecarriage; means to adjust the carriage and barrel longitudinally withrelation to the tool; and mechanical pusher means supported by the frameto engage the plunger stem and force the lunger inwardly, the saidpusher means,

caring means, clamping means, and tool driving connection being adaptedto permit the barrel, the tool and the plunger to be removedtransversely as a unit from the carriage and the supporting frame.

In testimony whereof I hereunto aflix my signature.

JACOB LOWE YOUNG.

